OWLAPI : HermiT reasoner thows "UnsupportedDatatypeException" for data type from imported Ontology

Question

I have 2 ontologies (generated through Protege).

A ontology (A.owl) :-

<?xml version="1.0"?>
<!DOCTYPE rdf:RDF [
    <!ENTITY owl "http://www.w3.org/2002/07/owl#" >
    <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#" >
    <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#" >
    <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
]>
<rdf:RDF xmlns="http://www.semanticweb.org/ontologies/A#"
     xml:base="http://www.semanticweb.org/ontologies/A"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:owl="http://www.w3.org/2002/07/owl#"
     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
    <owl:Ontology rdf:about="http://www.semanticweb.org/ontologies/A">
        <owl:imports rdf:resource="http://www.semanticweb.org/ontologies/Z"/>
    </owl:Ontology>
    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Classes
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->
    <!-- http://www.semanticweb.org/ontologies/A#A -->
    <owl:Class rdf:about="http://www.semanticweb.org/ontologies/A#A">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/ontologies/A#B"/>
    </owl:Class>
    <!-- http://www.semanticweb.org/ontologies/A#B -->
    <owl:Class rdf:about="http://www.semanticweb.org/ontologies/A#B"/>
</rdf:RDF>
<!-- Generated by the OWL API (version 3.5.1) http://owlapi.sourceforge.net -->

Z ontology (Z.owl) :-

<?xml version="1.0"?>
<!DOCTYPE rdf:RDF [
    <!ENTITY owl "http://www.w3.org/2002/07/owl#" >
    <!ENTITY xsd "http://www.w3.org/2001/XMLSchema#" >
    <!ENTITY rdfs "http://www.w3.org/2000/01/rdf-schema#" >
    <!ENTITY rdf "http://www.w3.org/1999/02/22-rdf-syntax-ns#" >
]>
<rdf:RDF xmlns="http://www.semanticweb.org/ontologies/Z#"
     xml:base="http://www.semanticweb.org/ontologies/Z"
     xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
     xmlns:owl="http://www.w3.org/2002/07/owl#"
     xmlns:xsd="http://www.w3.org/2001/XMLSchema#"
     xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#">
    <owl:Ontology rdf:about="http://www.semanticweb.org/ontologies/Z"/>
    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Datatypes
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->
    <!-- http://www.semanticweb.org/ontologies/Z#myName -->
    <rdfs:Datatype rdf:about="http://www.semanticweb.org/ontologies/Z#myName"/>
    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Object Properties
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->
    <!-- http://www.semanticweb.org/ontologies/Z#myProp -->
    <owl:ObjectProperty rdf:about="http://www.semanticweb.org/ontologies/Z#myProp"/>
    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Data properties
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->
    <!-- http://www.semanticweb.org/ontologies/Z#name -->
    <owl:DatatypeProperty rdf:about="http://www.semanticweb.org/ontologies/Z#name">
        <rdfs:range rdf:resource="http://www.semanticweb.org/ontologies/Z#myName"/>
    </owl:DatatypeProperty>
    <!-- 
    ///////////////////////////////////////////////////////////////////////////////////////
    //
    // Classes
    //
    ///////////////////////////////////////////////////////////////////////////////////////
     -->
    <!-- http://www.semanticweb.org/ontologies/Z#X -->
    <owl:Class rdf:about="http://www.semanticweb.org/ontologies/Z#X">
        <rdfs:subClassOf rdf:resource="http://www.semanticweb.org/ontologies/Z#Y"/>
    </owl:Class>
    <!-- http://www.semanticweb.org/ontologies/Z#Y -->
    <owl:Class rdf:about="http://www.semanticweb.org/ontologies/Z#Y"/>
</rdf:RDF>
<!-- Generated by the OWL API (version 3.5.1) http://owlapi.sourceforge.net -->

I have imported Z.owl inside A.owl. When I run the HermiT reasoner with A ontology. It throws and org.semanticweb.HermiT.datatypes.UnsupportedDatatypeException Exception.

Exception Details :-

Exception in thread "main" org.semanticweb.HermiT.datatypes.UnsupportedDatatypeException: HermiT supports all and only the datatypes of the OWL 2 datatype map, see 
http://www.w3.org/TR/owl2-syntax/#Datatype_Maps. 
The datatype 'http://www.semanticweb.org/ontologies/Z#myName' is not part of the OWL 2 datatype map and 
no custom datatype definition is given; 
therefore, HermiT cannot handle this datatype.

My JAVA Code is :-

Configuration reasonerConf = new Configuration();
            reasonerConf.throwInconsistentOntologyException = false;
ReasonerFactory factory = new ReasonerFactory();
OWLReasoner reasoner = factory.createReasoner(owlOntology, reasonerConf); //Line where it throws above Exception

owlOntology is current working ontology which is 'A' loaded into owlManager (OWLOntologyManager). 'Z' ontology is also in this owlManager.

I tried to run HermiT reasoner in protege but it doesn't throw any exception there.

Answer 1

You declared a datatype:

<rdfs:Datatype rdf:about="http://www.semanticweb.org/ontologies/Z#myName"/>

but it has no associated definition. What is its lexical form? Is "foo"^^ex:myName a legal instance or not? Is it equivalent as a value to "FOO"^^ex:myName or not? HermiT doesn't have a way to know the answer to these questions, and thus complains:

The datatype 'http://www.semanticweb.org/ontologies/Z#myName' is not part of the OWL 2 datatype map and no custom datatype definition is given; therefore, HermiT cannot handle this datatype.

You'll need to provide some kind of definition for this datatype that HermiT can understand, or perhaps use datatype facets instead.